WLANs are becoming increasingly popular access networks, both in public areas such as hotels, airports, train stations, conference facilities, as well as in proprietary areas such as in company buildings. Corporations install WLANs on their premises to allow freedom of movement to their personnel while providing a relatively high bandwidth compared with legacy wireless networks such as GSM (=Global System for Mobile Communication).
Another development of the past years has been the growing use of IP-based data networks for the transmission of real-time data such as voice and video (IP=Internet Protocol). Several standards dealing with VoIP applications have been introduced, such as the codec standards G.711 and G.729, and the transmission protocol RTP (VoIP=Voice over IP; codec=encoding/decoding; RTP=Real-Time Transport Protocol).
Until recently, subscribers used a WLAN network for non-realtime applications, only, e.g., to connect their browser to the Internet. However, today's WLANs are challenged with the task to handle also real-time applications, e.g., VoWLAN (=Voice over WLAN). After all, subscribers of a VoWLAN solution expect the same voice quality, reliability and functionality as with their legacy PSTN (=Public Switched Telephone Network) telephone or GSM mobile phone.